1. Field of the Invention
This invention relates generally to methods of moving bodies, such as pallets containing components, and more specifically relates to a method of moving such pallets vertically from one level to another.
2. Description of the Related Art
It is well known in the manufacturing industry to place component parts on pallets that rest upon a conveyor and are transported thereby, as shown in U.S. Pat. No. 6,990,796 to Schnipke, et al., which is incorporated herein by reference. Such pallets can contain component parts to which other components are added. Similarly, such pallets can contain component parts that are removed from the pallet and used in an assembly process.
The pallets referred to above can be transported along an assembly line in a manufacturing facility by resting the downwardly facing surface of each pallet upon the upwardly facing surface of a conveyor belt. Such a belt is capable of transporting pallets long distances along a horizontal path, but cannot readily move pallets significant vertical distances in a small space. Such vertical movement normally must be made by short runs of steeply angled tracks, which are prone to slipping due to the materials of which the tracks and pallets are made.
It is known to provide an angled track to allow a pallet to fall vertically under the force of gravity from one level to another. However, if there are component parts on the falling pallet that must be removed during the transition from one level to the other, removal of the object from the pallet during the transition presents a problem of timing due to the relative motion. Even if the pallet is not in motion during removal of the object and the object is removed by a high precision robot, the problem of precisely locating the pallet during removal so that the position of the object thereon is known exactly still exists.
Therefore, the need exists for a method of moving pallets vertically from one level to another while permitting removal of objects from the pallets.